[ OK ] Started getty on tty2-tty6 if dbus and logind are not available. [ OK ] Found device /dev/ttyS0. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Reached target Login Prompts. [ OK ] Started OpenBSD Secure Shell server. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.35' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 34.042326] ================================================================== [ 34.049844] BUG: KASAN: use-after-free in ex_handler_refcount+0x18f/0x1c0 [ 34.056794] Write of size 4 at addr ffff8880ade21198 by task syz-executor219/8081 [ 34.064409] [ 34.066044] CPU: 1 PID: 8081 Comm: syz-executor219 Not tainted 4.19.187-syzkaller #0 [ 34.073921] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.083273] Call Trace: [ 34.085878] dump_stack+0x1fc/0x2ef executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.089519] print_address_description.cold+0x54/0x219 [ 34.094810] kasan_report_error.cold+0x8a/0x1b9 [ 34.099556] ? ex_handler_refcount+0x18f/0x1c0 [ 34.104136] __asan_report_store4_noabort+0x88/0x90 [ 34.109161] ? ex_handler_refcount+0x18f/0x1c0 [ 34.113750] ex_handler_refcount+0x18f/0x1c0 [ 34.118187] ? ex_handler_clear_fs+0xb0/0xb0 [ 34.122595] fixup_exception+0x8a/0xd0 [ 34.126471] do_trap+0x61/0x250 [ 34.129752] do_error_trap+0x15d/0x310 [ 34.133748] ? math_error+0x310/0x310 [ 34.137544] ? __lock_acquire+0x6de/0x3ff0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.141783] ? __noinstr_text_end+0x7617/0x77e7 [ 34.146449] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.151292] invalid_op+0x14/0x20 [ 34.154751] RIP: 0010:__noinstr_text_end+0x7617/0x77e7 [ 34.160026] Code: 8d 0e 0f 0b 48 8d 8d 80 00 00 00 0f 0b 48 8d 8d 80 00 00 00 0f 0b 48 8d 8b 80 00 00 00 0f 0b 49 8d 4c 24 18 0f 0b 48 8d 4d 18 <0f> 0b 49 8d 8d 80 00 00 00 0f 0b 49 8d 4d 00 0f 0b 48 8d 8b e4 00 [ 34.178949] RSP: 0018:ffff888095557bc0 EFLAGS: 00010297 [ 34.184316] RAX: ffff8880b4792280 RBX: 0000000000000004 RCX: ffff8880ade21198 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.191673] RDX: 0000000000000000 RSI: ffffffff87dcb8f8 RDI: ffff8880ade21180 [ 34.198944] RBP: ffff8880ade21180 R08: 0000000000000000 R09: 0000000000000000 [ 34.206214] R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880b167c900 [ 34.213490] R13: ffff8880b167c900 R14: ffff8880ade21180 R15: ffff8880b5b8ba20 [ 34.220777] ? nfc_llcp_local_put+0x18/0x1b0 [ 34.225198] ? nfc_llcp_sock_free+0x220/0x220 [ 34.229696] llcp_sock_destruct+0x7b/0x140 [ 34.233933] __sk_destruct+0x4b/0x8a0 [ 34.237741] __sk_free+0x165/0x3b0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.241285] sk_free+0x3b/0x50 [ 34.244480] llcp_sock_release+0x37a/0x520 [ 34.248740] __sock_release+0xcd/0x2a0 [ 34.252634] ? __sock_release+0x2a0/0x2a0 [ 34.256809] sock_close+0x15/0x20 [ 34.260270] __fput+0x2ce/0x890 [ 34.263577] task_work_run+0x148/0x1c0 [ 34.267461] do_exit+0xbf3/0x2be0 [ 34.270907] ? lock_downgrade+0x720/0x720 [ 34.275076] ? mm_update_next_owner+0x650/0x650 [ 34.279741] ? up_read+0x17/0x110 [ 34.283209] ? __do_page_fault+0x180/0xd60 [ 34.287446] do_group_exit+0x125/0x310 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.291334] __x64_sys_exit_group+0x3a/0x50 [ 34.295684] do_syscall_64+0xf9/0x620 [ 34.299496] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.304685] RIP: 0033:0x43e989 [ 34.307881] Code: 00 49 c7 c0 c0 ff ff ff be e7 00 00 00 ba 3c 00 00 00 eb 12 0f 1f 44 00 00 89 d0 0f 05 48 3d 00 f0 ff ff 77 1c f4 89 f0 0f 05 <48> 3d 00 f0 ff ff 76 e7 f7 d8 64 41 89 00 eb df 0f 1f 80 00 00 00 [ 34.326776] RSP: 002b:00007fff7d34c948 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 34.334477] RAX: ffffffffffffffda RBX: 00000000004b02f0 RCX: 000000000043e989 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.341754] RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 [ 34.349027] RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000001 [ 34.356299] R10: 0000000000080800 R11: 0000000000000246 R12: 00000000004b02f0 [ 34.363571] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 [ 34.370845] [ 34.372464] Allocated by task 1: [ 34.375845] kmem_cache_alloc_trace+0x12f/0x380 [ 34.380525] nfc_llcp_register_device+0x45/0x9b0 [ 34.385284] nfc_register_device+0x6d/0x360 [ 34.389614] nfcsim_device_new+0x333/0x5af executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.393854] nfcsim_init+0x71/0x14d [ 34.397482] do_one_initcall+0xf1/0x740 [ 34.401460] kernel_init_freeable+0x9a6/0xa98 [ 34.406025] kernel_init+0xd/0x1b6 [ 34.409558] ret_from_fork+0x24/0x30 [ 34.413262] [ 34.414886] Freed by task 8083: [ 34.418160] kfree+0xcc/0x210 [ 34.421259] nfc_llcp_local_put+0x155/0x1b0 [ 34.425587] llcp_sock_destruct+0x7b/0x140 [ 34.429834] __sk_destruct+0x4b/0x8a0 [ 34.433693] __sk_free+0x165/0x3b0 [ 34.437226] sk_free+0x3b/0x50 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.440427] llcp_sock_release+0x37a/0x520 [ 34.444665] __sock_release+0xcd/0x2a0 [ 34.448552] sock_close+0x15/0x20 [ 34.452009] __fput+0x2ce/0x890 [ 34.455291] task_work_run+0x148/0x1c0 [ 34.459179] do_exit+0xbf3/0x2be0 [ 34.462634] do_group_exit+0x125/0x310 [ 34.466520] __x64_sys_exit_group+0x3a/0x50 [ 34.470848] do_syscall_64+0xf9/0x620 [ 34.474651] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.479836] [ 34.481458] The buggy address belongs to the object at ffff8880ade21180 [ 34.481458] which belongs to the cache kmalloc-2048 of size 2048 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.494283] The buggy address is located 24 bytes inside of [ 34.494283] 2048-byte region [ffff8880ade21180, ffff8880ade21980) [ 34.506202] The buggy address belongs to the page: [ 34.511124] page:ffffea0002b78800 count:1 mapcount:0 mapping:ffff88813bff0c40 index:0x0 compound_mapcount: 0 [ 34.521094] flags: 0xfff00000008100(slab|head) [ 34.525673] raw: 00fff00000008100 ffffea0002b75d88 ffffea0002b7c408 ffff88813bff0c40 [ 34.533544] raw: 0000000000000000 ffff8880ade20080 0000000100000003 0000000000000000 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.541410] page dumped because: kasan: bad access detected [ 34.547110] [ 34.548734] Memory state around the buggy address: [ 34.553701] ffff8880ade21080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 34.561052] ffff8880ade21100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 34.568415] >ffff8880ade21180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.575769] ^ [ 34.579919] ffff8880ade21200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.587279] ffff8880ade21280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.594629] ================================================================== [ 34.601983] Disabling lock debugging due to kernel taint [ 34.616920] Kernel panic - not syncing: panic_on_warn set ... [ 34.616920] [ 34.624306] CPU: 1 PID: 8081 Comm: syz-executor219 Tainted: G B 4.19.187-syzkaller #0 [ 34.633571] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.642917] Call Trace: [ 34.645511] dump_stack+0x1fc/0x2ef [ 34.649139] panic+0x26a/0x50e [ 34.652331] ? __warn_printk+0xf3/0xf3 [ 34.656223] ? preempt_schedule_common+0x45/0xc0 [ 34.660979] ? ___preempt_schedule+0x16/0x18 [ 34.665392] ? trace_hardirqs_on+0x55/0x210 [ 34.669719] kasan_end_report+0x43/0x49 [ 34.673695] kasan_report_error.cold+0xa7/0x1b9 [ 34.678365] ? ex_handler_refcount+0x18f/0x1c0 [ 34.682947] __asan_report_store4_noabort+0x88/0x90 [ 34.687961] ? ex_handler_refcount+0x18f/0x1c0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.692540] ex_handler_refcount+0x18f/0x1c0 [ 34.696952] ? ex_handler_clear_fs+0xb0/0xb0 [ 34.701361] fixup_exception+0x8a/0xd0 [ 34.705252] do_trap+0x61/0x250 [ 34.708538] do_error_trap+0x15d/0x310 [ 34.712427] ? math_error+0x310/0x310 [ 34.716233] ? __lock_acquire+0x6de/0x3ff0 [ 34.720470] ? __noinstr_text_end+0x7617/0x77e7 [ 34.725146] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.729994] invalid_op+0x14/0x20 [ 34.733451] RIP: 0010:__noinstr_text_end+0x7617/0x77e7 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.738725] Code: 8d 0e 0f 0b 48 8d 8d 80 00 00 00 0f 0b 48 8d 8d 80 00 00 00 0f 0b 48 8d 8b 80 00 00 00 0f 0b 49 8d 4c 24 18 0f 0b 48 8d 4d 18 <0f> 0b 49 8d 8d 80 00 00 00 0f 0b 49 8d 4d 00 0f 0b 48 8d 8b e4 00 [ 34.757623] RSP: 0018:ffff888095557bc0 EFLAGS: 00010297 [ 34.762984] RAX: ffff8880b4792280 RBX: 0000000000000004 RCX: ffff8880ade21198 [ 34.770254] RDX: 0000000000000000 RSI: ffffffff87dcb8f8 RDI: ffff8880ade21180 [ 34.777523] RBP: ffff8880ade21180 R08: 0000000000000000 R09: 0000000000000000 [ 34.784792] R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880b167c900 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.792068] R13: ffff8880b167c900 R14: ffff8880ade21180 R15: ffff8880b5b8ba20 [ 34.799347] ? nfc_llcp_local_put+0x18/0x1b0 [ 34.803766] ? nfc_llcp_sock_free+0x220/0x220 [ 34.808271] llcp_sock_destruct+0x7b/0x140 [ 34.812509] __sk_destruct+0x4b/0x8a0 [ 34.816317] __sk_free+0x165/0x3b0 [ 34.819861] sk_free+0x3b/0x50 [ 34.823059] llcp_sock_release+0x37a/0x520 [ 34.827299] __sock_release+0xcd/0x2a0 [ 34.831191] ? __sock_release+0x2a0/0x2a0 [ 34.835342] sock_close+0x15/0x20 [ 34.838807] __fput+0x2ce/0x890 [ 34.842091] task_work_run+0x148/0x1c0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.845981] do_exit+0xbf3/0x2be0 [ 34.849440] ? lock_downgrade+0x720/0x720 [ 34.853588] ? mm_update_next_owner+0x650/0x650 [ 34.858280] ? up_read+0x17/0x110 [ 34.861734] ? __do_page_fault+0x180/0xd60 [ 34.865972] do_group_exit+0x125/0x310 [ 34.869881] __x64_sys_exit_group+0x3a/0x50 [ 34.874202] do_syscall_64+0xf9/0x620 [ 34.878006] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.883190] RIP: 0033:0x43e989 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 34.886379] Code: 00 49 c7 c0 c0 ff ff ff be e7 00 00 00 ba 3c 00 00 00 eb 12 0f 1f 44 00 00 89 d0 0f 05 48 3d 00 f0 ff ff 77 1c f4 89 f0 0f 05 <48> 3d 00 f0 ff ff 76 e7 f7 d8 64 41 89 00 eb df 0f 1f 80 00 00 00 [ 34.905274] RSP: 002b:00007fff7d34c948 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 34.912984] RAX: ffffffffffffffda RBX: 00000000004b02f0 RCX: 000000000043e989 [ 34.920254] RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 [ 34.927526] RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000001 [ 34.934881] R10: 0000000000080800 R11: 0000000000000246 R12: 00000000004b02f0 [ 34.942154] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 [ 34.950068] Kernel Offset: disabled [ 34.953686] Rebooting in 86400 seconds..